| Porous β-tricalcium phosphate (β-TCP) ceramics have many important biomedical applications, such as bone defect fillers, tissue engineering scaffolds and drug delivery systems. At present, there are many ways to prepare porous β-TCP ceramics, and the products prepared in different ways have different performance. In this paper, a new fabrication method was introduced to prepare porous β-TCP ceramics.The new method involved the use of cold isostatic pressure forming and the use of pore forming materials. Cold isostatic pressure forming can produce high intensity blank, so making use of it and pore forming materials can produce a porous ceramics with controllable porosity, pore size and shape can be obtained. In this paper the possibility to integrate their specialties, thereby to get a new mixed method, which can produce porous ceramics with their advantages, such as high intensity, controllable porosity, pore size and shape, was discussed.The preparing process is following. β-TCP powder and bioglass powder were mixed in weight ratio of 1:4. Polyvinyl alcohol solution was added to the powder mixture and naphthalene particles by spraying. Firstly, the mixture of β-TCP powder, bioglass powder and naphthalene particles was pressed in a mold by hand and then pressed with cold isostatic pressure method. During the preparation, naphthalene was used as pore forming material. The-TCP blanks were sintered in an electric muffle furnace according to following procedure: First the temperature rise in a low speed of 2℃/min , when it reach to 80℃ and keep it for 1 hours to burn off the naphthalene. Second the temperature will go to 140℃ continuously at the same speed and then stay there for 0.5h. Third the temperature will reach 900℃ at the speed of 5℃/min. The β-TCP ceramic is sintered at 900℃ and stays in the temperature for 1 hours. Last it will be cooled in air.The crucial factor is that the mixing process of powder mixture and naphthalene particles, which will determine the configuration of the final products. Besides, the cold isostatic pressure forming is also very important, because it can strengthen the intensity of the blanks and improve sintering of the blanks.The DSC analysis showed that the missing process of naphthalene particles will complete at the temperature of 139.8°C and it would bring in no impurity when it was burned up. By XRD analysis, it is found that the-TCP is a main crystal phase of the porous ceramics, and with a few a-TCP and HA crystal phase .P-TCP powder and naphthalene was mixed in volume ratio. The ratio, size and shape of naphthalene will decide the porosity, pore size and pore shape of the final porous ceramics, and they also impacted strength of the ceramics. After the experiments, we got the following results (Each Data was the average of 5 specimens): with the ratio of 50%, 60%, 70% and 80%, the porosity was 55.3%, 61.7%, 74.2% and 86.5% respectively, the compression strength was 3.12MPa, 1.67MPa, 1.09Mpa and 0.062Mpa respectively. The products were also analyzed through SEM photographs and 3D imagines. There were abundant pores in the products with irregular shape and interconnected well. Especially there were very small pores on the surface of pore wall. These results would be helpful to explain the opening porosity and the strength data.Removing extremely small pores on the wall was capable of improving the strength performance, and to be used in industry the process should be more simple. To sum up, the method has vast foreground in producing porous materials.
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